A steam pressing iron normally has a reservoir for the water that is to be heated to generate the steam, a sole plate, heating elements for heating at least the sole plate, and a passage or conduit system for conducting steam to the bottom surface of the plate. The combination of the steam with the heat from the sole plate is extremely effective in smoothing wrinkles.
Steam is generated in a standard system by dripping the water from the reservoir onto the inner surface of the sole plate, which hotter than 100.degree. C. This water vaporizes instantly and passes out of the iron through holes in the sole plate. Such an arrangement therefore must have its sole plate above 100.degree. C., which is too hot for some delicate synthetic-resin textiles, and can normally only produce a limited volume of steam.
In another arrangement there is a separate heater for vaporizing the water. Such an arrangement can generate a large volume of steam, which is particularly useful in heavy-duty commercial use. In addition it allows the sole plate to be relatively cool, 80.degree. C. to 90.degree.. Nonetheless the equipment is fairly complex and bulky, and is inefficient in that the steam cools some 10.degree. C. in moving to the goods.